Surface finishing is a term for a broad range of industrial processes that alter the surface of a manufactured item. Surface finishing of a manufactured item, such as the surface of a metal component, is often performed to achieve particular properties. Such properties may include functional properties such as wettability, solderability, corrosion or tarnish resistance, and so on. Such properties may also include visual properties such as causing a surface to have a particular appearance.
A manufactured item, such as the surface of a metal component, may be finished to achieve a particular appearance by cutting or otherwise forming a number of fine, proximate grooves into the surface utilizing a lathe, router, or other process. However, the proximity of the cut or otherwise formed grooves may diffract white light shone upon the surface. This may result in a rainbow effect caused be the diffracting of the white light into various of the colored light components, altering the appearance of the manufactured item.